CHAPTER XIII 



pointed and curve inward ; they remain on the tree several years 

 without opening. 



In classifying Angiosperms, the system adopted in Campbell's text 

 book, that of the German botanist, Eichler, is followed. In studying 

 seedlings, Chapter II, the distinction between monocotyledons and 

 dicotyledons was noted. In their earliest stages, both exogenous and 

 endogenous stems consist of pith in which woody fibers are scattered, 

 but the woody bundles of the exogen soon form a ring surrounded, 

 as noted in Chapter VIII, Supplement, by a cambium layer that adds 

 each year new rings of wood and bark. In endogenous stems, the 

 woody bundles remain scattered throughout the pith, and, while near 

 the circumference they are more numerous, rendering the tissue 

 firm and strong, there is no cylinder of wood, no true cambium, 

 and hence no rings of annual growth. Some endogenous stems do 

 not increase at all in diameter after the outside tissues are fully 

 formed, a few increase slowly by the interposition of woody fibres, 

 but by far the greater number of endogens have no perennial stems 

 above ground Short underground perennial stems, that is, root- 

 stocks, bulbs, corms and the like, are very common in this group. 

 Other common characteristics, as the children will discover for them- 

 selves, are entire, parallel-veined, and often, long, vertical leaves ; and 

 flowers whose parts are in threes. 



Of the group Iviliflorse, the order Liliacese alone has two thousand 

 species, many of these common in cultivation, so that material for 

 the study of family traits is not difficult to obtain. The lily-of-the- 

 valley, tulips, crown imperial and some other favorite garden plants 

 in more humid climates, are rather rare in California ; but several of 

 the lily-like plants enumerated in the Reader are common. The 

 smilax, or more correctly the Mersiphyllum, blooms very freely 

 early in the year ; its little star-like, white lilies have a delicious 

 fragrance, and attract guests in throngs. The foliage of this plant 

 is unique ; the true leaves are reduced to mere scales in whose axils 

 grow the flowers and also the apparent leaves, which are really modi- 

 fied branches. Besides the native lilies mentioned in Chapter VII 

 and its Supplement, and the Mariposa, Chapter IX, some others may 

 have been encountered before the children reach this chapter. There 

 are several very handsome species of native Brodiaeas, some of them 

 now under cultivation ; B. minor, Wats., with umbels of large violet 

 flowers is rather common in Southern California ; B. laxa, Wats., 

 sometimes called Ithuriel's spear, has still larger umbels ; it is rare 

 in the south, but fairly common in rich, shaded soil further north ; 

 some of the species of Brodisea are white, yellow, and even scarlet, 



101 



